Last night the Worrybomb had hiccups. For a good hour or so every few seconds it would jolt. It was difficult to work out which bit was making the movement, but it was pretty strong stuff according to Mrs Wb.
I have read its something very similar to normal hiccups, but rather than air, they drink/breath amniotic fluid and this sometimes causes the same type of oesophageal reflex and that also that the hiccups help to develop the muscles that the baby needs to breathe when it is born.
Did some reading on the web about it this morning, not masses of information and much is anecdotal but they seem to think only the more mature fetuses do this because of the development of the central nervous system. So all good stuff then, just glad its not me with them 🙂